Different types of flexible and elastic textile structures having an ability to conduct electricity or to influence electromagnetic fields have been disclosed for certain medical and physiological monitoring applications. For example, U.S. Pat. No. 6,341,504 to Cynthia L. Istook (assigned to VivoMetrics®, Inc., Ventura, Calif., USA) discloses a composite elastic fabric construction for apparel applications of the type used in physiological monitoring wherein the stretching and stretch-recovery of the composite elastic fabric changes the inductance of an electrically conductive curved wire affixed to or incorporated in the composite fabric. VivoMetrics® Inc. is the maker the Lifeshirt™, which incorporates the flexible electrically conductive textile structure of Istook and is used primarily for physiological monitoring and other ambulatory wearer measurement capabilities. In general, the Istook structure requires that one or more conducting wires be stitched to the face of an elastic band structure in order to form the curved wire geometry for the intended application.
PCT publication WO 2003/087451A2 to Vikram Sharma (“Sharma”) discloses a tubular knit fabric system comprising an electrically insulating yarn, a stretch yarn, and a “functional” yarn knitted together to form a tubular knit fabric. In Sharma, the functional yarn is electrically conductive, having a resistance of 0.01 ohm/meter to 5000 ohm/meter. The “functional” yarn is embedded within the tubular knit in a continuous spiral that extends the length of a sleeve formed from the tubular knit. Body portions, such as limbs, are surrounded by a portion of the tubular fabric to measure physiological signs. In addition, these tubular knit fabrics disclosed by Sharma are adaptable for use in a narrow elastic band configuration in which the functional yarns serve as parallel conductors for electrical signals. A disadvantage of Sharma's narrow elastic band structures is that the functional yarns or wires must be knitted simultaneously into the structure with all other components.
In addition to electrically conducting elements, optical fibers for light conduction have been disclosed for incorporation into garments. For example, U.S. Pat. No. 6,315,009 to Sundaresan Jayaraman et al. (assigned to Georgia Tech Research Corp.) (“Jayaraman”) discloses a full-fashioned continuously woven garment consisting of a comfort component and sensing component of the base fabric. According to Jayaraman, the sensing component can be an electrically conductive component or a penetration sensing component. For example, the penetration sensing component can be an optical conductor such as plastic optical fiber. A disadvantage of the Jayaraman construction is the need to simultaneously weave directly into the tubular fabric or garment the elastic yarn and the functional component(s), e.g. plastic optical fiber.
The above references incorporate functional components, such as electrical conductors, through the use of fabric structures of a woven or knitted type. Such functional components can have poor compatibility with conventional textiles. Moreover, such functional components generally cause difficulties in conventional fabric forming processes (e.g. weaving, knitting, seamless knitting). For example, wires, small cables, and plastic optical fibers often match poorly with typical textile fibers because of their fragility, elastic modulus, extensibility, and tensile strength. In particular, such disadvantages are notable where elastic recovery and flexibility from the structure or garment is desired and where the ability to wash or launder a garment is desired. Thus, flexible and elastic textile structures are needed that can overcome one or more deficiencies of the prior art.
The art continues to seek structures with elements able to conduct electricity, conduct light, or influence electromagnetic fields for use in certain medical and/or physiological monitoring applications, as well as industrial and interconnect applications, wherein the structures do not have at least one of the deficiencies mentioned above. An ability to provide a launderable garment that incorporates functional elements into flexible textile-like structures without the need to knit or weave such elements would be highly desirable.